The Pico Lite may perform better if the LR41 Alkaline cells were replace with the Silver Oxide versions i.e. the 392 silver oxide watch battery cell, giving a flatter discharge curve and higher capacity (45 mAhrs compared to 30 mAhrs, i.e. 50% improvement in capacity) and much better extended temperature use and better storage lifetime. A set of 4 392s would cost around $3.

As always there is a compromise between the size of the flashlight and its performance. The Pico Lite is half the size of the smallest AAA flashlight available, but its performance will be less than half that of the AAA flashlight, but that it just the nature of scaling down the size of the flashlight. Once you decide to make a flashlight smaller than a AAA cell flashlight, there are no easy choices to be made with regard to the battery type, chemistry etc due to limitations on the cells availability, capacity, voltage etc.